The present invention relates to a vacuum adjustment valve, particularly for thoracic drainage devices.
It is known that vacuum is used in many clinical situations in order to increase the effectiveness of drainage or, for example, to stabilize the position of the lungs in case of pneumothorax or pneumonotomy.
In all these situations the applied level of vacuum is to always be correctly controlled, both because it takes into account the clinical condition of the patient and most importantly because its uncontrolled increase can be considerably dangerous for the safety of the patient.
Vacuum in drainage devices is normally controlled by means of a so-called water seal valve having a water column arranged in parallel to the collection vessel that is connected to the patient; said solution is usually an integral part of the drainage system.
The continuous aspiration of air from the column indicates that the intended vacuum has been reached.
The height of the water column, typically between 10 and 20 centimeters, determines the intended level of vacuum.
Said valves are valid from a functional point of view, but they suffer the drawback that they are very noisy due to the continuous bubbling of air in the water column; this characteristic is particularly unpleasant for the patient especially at night, also since the drainage system remains connected to the patient for several days.
Another problem is constituted by the fact that by using the water seal valve, the drainage device must not be tipped, since the adjustment of the water column would otherwise be lost; moreover, in the water column valve the level of the water varies due to evaporation, with a consequent reduction in the applied vacuum.
In order to try to obviate these drawbacks, Italian patent No. 1293811 discloses a vacuum adjustment valve which is substantially constituted by a flexible tubular element associated with adjustable elastic means, and is interposed on the air intake duct.
The tubular element is connected to a plate having an opening which can hermetically engage an inlet which is connected to a drainage device.
The tubular element is surrounded by an environment at atmospheric pressure, so that when the degree of vacuum increases the tubular element is subjected both to radial contraction, which causes the compression of the spring, and to an axial thrust on the surface of the plate, so that automatic compensation occurs.
While the above solution is valid in many cases, it is however difficult to set and in particular it has not shown sufficiently uniform response; accordingly, it has failed to provide constant results.
The aim of the invention is to solve the above problem by providing a vacuum adjustment valve, particularly for thoracic drainage devices, which is particularly sensitive and is capable of providing at all times a uniform response which is a direct function of the intake air stream.
Within the scope of this aim, a particular object of the invention is to provide a valve which, in case of sudden increases in the level of vacuum, is capable of reacting in real time, producing an immediate reduction of the degree of vacuum, thus preventing transmission of suction level peak to the drainage device.
Another object of the present invention is to provide a valve which can operate in any position, can be easily set with optimum repeatability of its results, and is also able of giving the greatest assurances of reliability and safety in use.
Another object of the present invention is to provide a valve which can be easily obtained starting from commonly commercially available elements and materials and is competitive from a merely economical point of view.
These and other objects which will become better apparent hereinafter are achieved by a vacuum adjustment valve, particularly for thoracic drainage devices, according to the invention, characterized in that it comprises a valve body arranged in the air intake duct and forming a first region connected to said intake duct and a second region connected to a drainage device, a regulator being arranged between said regions, said regulator being struck by the air stream and being operatively connected to a flow control element which controls a port for connection between said second region and an environment at atmospheric pressure, adjustable elastic closure means acting on said flow control element.